stefanha

6 ms·

1.
by stefanha 1mo ago
It's not. In the demo video the exploit code is a Linux kernel module, not a userspace application.
2.
by stefanha 2mo ago
9P is a filesystem protocol (like NFS or CIFS) rather than a local file system (like btrfs or NTFS). It's used to share files between the host and the guest. That way there's no need to copy files between the host and the guest.
3.
by stefanha 2mo ago
virt-builder is an alternative to installing a guest OS from scratch. It has a selection of popular guest OSes template images that you can quickly install non-interactively. It's convenient when you don't want to manually install
4.
by stefanha 3mo ago
> The full build of all Git functionality in Rust is currently around 27M, but since a large part of it is a library, it could clearly be easily split up into domains of functionality - subcrates that do specific things. I downloaded v0.
5.
by stefanha 8mo ago
Link to the protocol specification: https://github.com/TrustTunnel/TrustTunnel/blob/master/PROTO... It's a thin HTTP/2 and HTTP/3 tunneling protocol for TCP, UDP, and ICMP traffic. It sho
6.
by stefanha 11mo ago
In Linux (Wayland) you can copy text from the terminal without pressing Ctrl+C at all. Just select the text. To paste it in another Window, press the middle mouse button. This is called the Primary Selection and is separate from the Clipboa
7.
by stefanha 11mo ago
@graveland Which Linux interface was used for the userspace block driver (ublk, nbd, tcmu-runner, NVMe-over-TCP, etc)? Why did you choose it? Also, were existing network or distributed file systems not suitable? This use case sounds like Ce
8.
by stefanha 1y ago
qemu-img convert supports copy_file_range(2) too. Was the `--copy-range-offloading` option used in the benchmark? It would be helpful to share the command-line and details of how benchmarks were run.
9.
by stefanha 1y ago
I'm the presenter of the talk, but not an io_uring kernel developer or security expert. The io_uring implementation is complex and the number of lines of code is non-trivial. On the other hand, as code matures and the number of bugs be
10.
by stefanha 1y ago
Donations are possible through PayPal: https://www.qemu.org/donations/ QEMU is a Software Freedom Conservancy member project like Git, OpenWRT, and many others. You can donate through the Conservancy link you posted an
11.
by stefanha 1y ago
It looks plausible: XFS's xfs_dio_write_end_io() updates the on-disk file size. Do you have a link to documentation that confirms this is true for Linux or POSIX filesystems? Edit: POSIX 1003.1-2017 defines fdatasync(2) behavior in 3.3
12.
by stefanha 1y ago
io_uring is available from RHEL 9.3 onward. The catch is that it's disabled by default and needs to be enabled at runtime via the "kernel.io_uring_disabled" sysctl.
13.
by stefanha 1y ago
Agreed, when metadata changes are involved then RWF_SYNC must be used. RWF_DSYNC is sufficient and faster when data is overwritten without metadata changes to the file.
14.
by stefanha 1y ago
The Linux RWF_DSYNC flag sets the Full Unit Access (FUA) bit in write requests. This can be used instead of fdatasync(2) in some cases. It only syncs a specific write request instead of the entire disk write cache.
15.
by stefanha 1y ago
There is ongoing discussion about this topic in the QEMU AI policy: https://lore.kernel.org/qemu-devel/20250625150941-mutt-send-...
16.
by stefanha 1y ago
The article mentions getting SPEC CPU running but doesn't share performance results or scalability results (now the CPU can decode twice as many instructions, etc). Can someone who has been following the research in this area share som
17.
by stefanha 2y ago
I'm not familiar with this stuff and don't have time to fully read the specs plus the required background reading. Here is my guess based on skimming the spec: The application may embed the VAPID public key while the VAPID private
18.
by stefanha 2y ago
In this direct to FCM model, does the application running on the untrusted user's device need to embed any sensitive credentials? What prevents someone else from impersonating my app or other users on my app?
19.
by stefanha 2y ago
Can you be specific about what cannot be configured on mounted embedded media? systemd follows the drop-in config file model where configuration snippets are placed into directories (like .d/ directories in Debian). It should not be ne
20.
by stefanha 2y ago
Keep in mind it doesn't magically wake up descheduled tasks. So it's necessary to go through the kernel if the destination task is not currently running on a CPU. The latency in that case will be similar to what we have today. And
21.
by stefanha 2y ago
Lots of cool hybrid container/VM ideas are being developed! Bootable Container Images are a standard for launching VMs from OCI images: https://containers.github.io/bootable/ crun-vm ( https://github.com
22.
by stefanha 2y ago
> the sound from musical instruments Pianoteq ( https://en.wikipedia.org/wiki/Pianoteq ) is a physically modeled collection of instruments (mostly pianos). Runs even on a Raspberry Pi and sounds like the real deal wit
23.
by stefanha 2y ago
There is even NVMe passthrough support via io_uring, so it's still possible to send custom NVMe commands when using io_uring instead of a userspace driver: https://www.usenix.org/system/files/fast24-joshi.pdf
24.
by stefanha 2y ago
Thank you! This quick overview is helpful: https://player.vimeo.com/video/922512661
25.
by stefanha 2y ago
I have a hard time getting a sense of what the display is really like from the website and the embedded video (it cuts too quickly, uses depth of field shots of the tablet, etc). Given that this is all about a new display, it would be nice
26.
by stefanha 2y ago
That's awesome, really looking forward to seeing more about PySheets!
27.
by stefanha 2y ago
Any chance of a video walkthrough or tutorial? I can't figure out what the workflow is and which use cases PySheets addresses from looking at the landing page. I don't want to register an account just to find out.
28.
by stefanha 2y ago
It reads like a patent. Patents enumerate all sorts of possible cases, some of them overlapping, some of them disjoint. Patents do this to claim as much of the idea space as possible, maximizing the reach of the patent. "It's this
29.
by stefanha 2y ago
I see what you mean. A "batteries included" standard library reduces the risk for obscure third-party dependencies. Qt comes to mind. It includes the kitchen sink and a lot of applications can be written without third-party depend
30.
by stefanha 2y ago
Hi, I'm the author. See the "The best approach we have today for run-time isolation is through sandboxing" part in the blog post. It covers sandboxing, which pledge(2) is an example of. My experience with sandboxing approache

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